The Role of Science in Solving the World's Emerging Water Problems

Organized by William Jury and Henry Vaux

October 8-10, 2004Irvine, CA

Meeting Overview:The 21st century promises to confront humankind with a host of new resource and environmental challenges, virtually all driven by continued population growth. The most recent population forecasts envision growth continuing at least through the majority of the 21st century, and perhaps beyond, with an expected peak world population of 9-11 billion. For the most part, the additional 3-5 billion people will be added to the poorer and resource-limited regions of the world, creating enormous challenges in the management of scarce resources and in the production of adequate quantities of food and fiber.

In particular, the incremental stresses that these additional people will place in the world's water resources will sharply intensify the existing world water scarcity and lead to a host of critical water management challenges. Thus, for example, the task of feeding an enlarged population will almost surely require the expansion of irrigated acreage world-wide with attendant increases in the demand for water. Already there are signs that food production advances are being overtaken by population growth. Worldwatch reports that grain production failed to match consumption in 10 of the last 15 years between 1987-2001, causing grainstocks to decline to lower and lower levels. The latest UN analysis estimates that 25,000 people are starving to death each day, and as many as 800 million are undernourished. Food production clearly needs to increase sharply in the years ahead to prevent widespread famine and disease. And, such increases in food production will invariably be accompanied by increases in water demand.

Although substantial effort is being focused on development of higher-yielding crops, a growing number of experts believe that water availability will become a limiting factor in crop production, and that water shortages will become chronic in some of the most populous regions of the world. In fact, a significant portion of today's crop production capacity may be ephemeral, because it relies on temporary water availability. Postel (1994) has estimated that as many as 500 million people today are being fed by crops grown with water obtained by groundwater overdraft, the majority in China and India. UN estimates project that at least 3 and as many as 7 billion people will live in chronically water-short areas by the end of the century. And on top of this dire forecast looms the uncertainty of climate change, which by recent estimates could decrease river flow supply to certain populous areas by as much as 20%.

Even in the face of prospective increases in demand, water supplies are also being lost at a growing rate from pollution, especially in poor countries undergoing rapid industrialization and urbanization. Water pollution is already a major cause of death in the world today, from diarrheal diseases, malaria, and parasitic infections. It is estimated that 1 billion people worldwide today lack access to clean water. Twice that many are estimated to lack adequate sanitation facilities. Virtually all of these people dwell in areas where sharp population increases are expected.

As the world scrambles to meet ever-growing water demands, the likelihood is that ecosystems will suffer untold damages. More than 50% of the world's wetlands have been lost since 1900, and as many as 80 fish species have become extinct. Sixty percent of the world's 227 largest rivers are subject to serious flow disruption from dams, diversions, and canals, leading to degradation of downstream ecosystems. Every day, 2 million tons of human waste are disposed of in rivers and streams. Moreover, our understanding of aquatic ecosystems and their water requirements is rudimentary at best. The task of maintaining and enhancing water based environments while providing water for basic human needs and economic growth will be enormous.

No one disputes that there is adequate water in the world to meet the needs of humanity. The world's problems are caused largely by regional and temporal shortages, lack of technology, and poor management. Science will play a critical role in determining whether we will be successful in addressing the daunting array of water problems that beset the world. While new science will be necessary and helpful, there is also a need to employ existing scientific principles on a wide scale if we are to address the water resource problems of today and develop effective propose solutions that can be implemented globally in the coming decades.